Rendering extended video in virtual reality

ABSTRACT

A method for transforming extended video data for display in virtual reality processes digital extended video data for display on a center screen and two auxiliary screens of a real extended video cinema. The method includes accessing, by a computer executing a rendering application, data that defines virtual screens including a center screen and auxiliary screens, wherein tangent lines to each of the auxiliary screens at their respective centers of area intersect with a tangent line to the center screen at its center of area at equal angles in a range of 75 to 105 degrees. The method includes preparing virtual extended video data at least in part by rendering the digital extended video on corresponding ones of the virtual screens; and saving the virtual extended video data in a computer memory. A corresponding playback method and apparatus display the processed data in virtual reality.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of International Patent ApplicationNo. PCT/US2018/016676 filed Feb. 2, 2018, which claims priority pursuantto 35 U.S.C. § 119(e) to U.S. Provisional Patent Application Ser. No.62/454,625 filed Feb. 3, 2017, which applications are herebyincorporated by reference in their entireties.

FIELD

The present disclosure relates to methods and apparatus for use ofextended video data in virtual reality.

BACKGROUND

“Extended video” is a term of art that refers to presentation of cinemacontent using three screens: a center screen, and auxiliary screen oneach side of the center screen. Each auxiliary screen is angled towardsthe audience, while the center screen faces the audience in atraditional manner. The auxiliary screens partially enclose the cinemaaudience along the sidewalls of the auditorium, providing a moreimmersive experience. Traditionally, cinematic content is produced onlyfor one screen located on the front wall of the auditorium, whichbecomes the center screen in an extended video setup. Recently, extendedcontent has been produced for display on the auxiliary screens ofextended video setups. One such extended video content is marketed underthe name ScreenX™. As used herein, “digital extended video data” meansvideo data for cinema presentation on a center screen and at least twoopposing auxiliary screens one on each side of the center screen whereinthe video data for each screen is distinct from video data for otherscreens, in a digital video format.

“Virtual reality” is a term that has been used for various types ofcontent that simulates immersion in a three-dimensional (3D) world,including, for example, various video game content, and animated filmcontent. Virtual reality (VR) and augmented reality (AR) have beenapplied to various types of immersive video stereoscopic presentationtechniques including, for example, stereoscopic virtual realityheadsets. Headsets and other presentation methods immerse the user in a3D scene. Lenses in the headset enable the user to focus on alightweight split display screen mounted in the headset only inches fromthe user's eyes. Different sides of the split display show right andleft stereoscopic views of video content, while the user's peripheralview is blocked. In another type of headset, two separate displays areused to show different images to the user's left eye and right eyerespectively. In another type of headset, the field of view of thedisplay encompasses the full field of view of eye including theperipheral view. In another type of headset, an image is projected onthe user's retina using controllable small lasers, mirrors or lenses.Either way, the headset enables the user to experience the displayedvirtual reality content more as if the viewer were immersed in a realscene.

The immersive effect of VR may be provided or enhanced by motion sensorsin the headset that detect motion of the user's head, and adjust thevideo display(s) accordingly. By turning his head to the side, the usercan see the virtual reality scene off to the side; by turning his headup or down, the user can look up or down in the virtual reality scene.The headset may also include tracking sensors that detect position ofthe user's head and/or body, and adjust the video display(s)accordingly. By leaning or turning, the user can see the virtual realityscene from a different point of view. This responsiveness to headmovement, head position and body position greatly enhances the immersiveeffect achievable by the headset. The user may also move around thescene, in some implementations. The user may be provided the impressionof being placed inside or “immersed” in the virtual reality scene. Asused herein, “immersive” encompasses both VR and AR.

Fully immersive, high quality content is sometimes more difficult toproduce than content prepared for a single screen, such as whenincorporating video shot on actual sets. At the same time, the currentmarket size for VR content is relatively small, compared tosingle-screen content. These economic realities have reduced theavailability of high-quality entertainment for VR users. One approach toincreasing the number of content titles available to VR users is toreformat traditional cinematic content for display on a “virtual screen”in a “virtual cinema” modeled in a VR-compatible data format, forexample by transforming 2D or 3D video content in a video texture ofscreen that matches the proportions and geometry of the screen for whichthe content was produced. Such reformatting of available content isrelatively cost-effective. Thus, a user can enjoy the same content asmade available for the cinema or home theater using a VR headset, as amatter of convenience or to avoid the cost of bulkier home theaterequipment.

The impression on the user of viewing traditional content in VR issimilar to watching the content in a traditional theater or hometheater, while also providing the content producer with the capacity toenhance some or all of the content for the VR environment, if desired.Placing the screen at some virtual distance from the rendered viewpoint,and optionally rendering theater seats between the viewpoint and thescreen, creates the impression of being in a theater. To fit the screendimensions, a portion of the VR screen space lacks video content,diminishing the immersive quality of the VR experience.

Extended video can similarly be formatted for display in VR, by modelingthe center and auxiliary screens and rendering a corresponding videotexture on each modeled screen. A common approach includes modeling thescreens so that all are visible at once, and so that the virtual screensmimic or resemble the actual extended video screens that the content isproduced for. The effect of this approach is shown in FIG. 1, showing anapproximation of a virtual reality screenshot 100 for a prior artvirtual extended video application. When the auxiliary screens ofextended video setups are modeled in virtual reality, the video contentappears in a relatively narrow band 110. A large portion 120 of thevirtual reality display merely displays black or other static content.As a result, the display of extended video in virtual reality degradesthe immersive effect of virtual reality even more so than withtraditional, single-screen video. Nor is there any obvious solution tothe problem of configuring extended video content so as to result in anappealing display for the typical VR user and avoid distortion of thevideo content or the need for extensive remastering.

It would be desirable, therefore, to develop new methods fortransforming extended video content for use with virtual reality headsetdisplay equipment, that overcome these and other limitations of theprior art, and enhance the appeal and enjoyment of narrative videocontent for new immersive technologies such as VR.

SUMMARY

This summary and the following detailed description are complementaryparts of an integrated disclosure, and may include redundant subjectmatter and/or supplemental subject matter. An omission in either sectiondoes not indicate priority or relative importance of any elementdescribed in the integrated application. Differences between thesections may include supplemental disclosures of alternativeembodiments, additional details, or alternative descriptions ofidentical embodiments using different terminology, as will be apparentfrom the respective disclosures.

In an aspect of the disclosure, a computer-implemented method fortransforming extended video data for display in virtual reality includesreceiving digital extended video data for display on a center screen andtwo auxiliary screens of a real extended video cinema. The method mayfurther include accessing, by a computer executing a renderingapplication, data that defines virtual screens including a center screenand auxiliary screens, wherein tangent lines to each of the auxiliaryscreens at their respective centers of area intersect with a tangentline to the center screen at its center of area at equal angles in arange of 75 to 105 degrees. In other words, the computer orients andpositions the virtual screens such that tangent lines or planesintersect at an angle within the stated range. The method may furtherinclude preparing virtual extended video data at least in part byrendering the digital extended video on corresponding ones of thevirtual screens, and saving the virtual extended video data in acomputer memory. In another aspect of the disclosure, a method forprocessing extended video data for display by a virtual reality displayapparatus, may include receiving, by a virtual reality displayapparatus, virtual extended video data for display that defines virtualscreens as described for the foregoing method, outputting the virtualextended video data for display using a stereographic display system ofthe VR headset, and optionally, displaying the virtual extended videodata on the display.

In aspects of either or both foregoing methods, the data that definesthe virtual screens may further define that the tangents to each of theauxiliary screens are parallel. The data that defines the virtualscreens may further define that each of the virtual screens ischaracterized by a having a cylindrical radius of curvature ‘R’ in aplane parallel to top and bottom edge of each virtual screen. In anotheraspect, the data that defines the virtual screens may further definethat a ratio R/z₂ wherein ‘z₂’ indicates height of each of the virtualscreens is in a range of 1 to 4. Either both of the foregoing methodsmay include accessing data that defines a virtual floor plane parallelto and located a distance ‘z₃’ below the bottom edge of each virtualscreen, wherein z₃ is equal to or within 20% of 0.9*z₂. The bottom edgesof the screens may be vertically aligned. The data that defines thevirtual screens may further define that each of the virtual screens hasa width ‘W’ measured along its respective one of the tangent lines suchthat a ratio W/z₂ is in a range of 1.8 to 3.6. The data that defines thevirtual screens may further define that the auxiliary screens face eachother and are spaced apart a distance ‘2C’ measured at their respectivecenters of area, wherein a ratio of 2C/W is in a range of 1 to 1.5. Inan alternative aspect, the data that defines the virtual screens maydefine that each of the virtual screens is characterized by a having aspherical radius of curvature with a common center.

Any of the foregoing methods may be implemented in any suitableprogrammable computing apparatus, by provided program instructions in anon-transitory computer-readable medium that, when executed by acomputer processor, cause the apparatus to perform the describedoperations. An apparatus may include a computer or system of computersused in video production. In other embodiments, an apparatus may includea virtual reality device, such as a headset or other display that reactsto movements of a user's head or body to provide the impression of beingplaced inside of the rendered scene.

To the accomplishment of the foregoing and related ends, one or moreexamples describe and enable features pointed out in the claims. Thefollowing description and the annexed drawings set forth in detailcertain illustrative aspects and are indicative of but a few of thevarious ways in which the principles of the examples may be employed.Other advantages and novel features will become apparent from thefollowing detailed description when considered in conjunction with thedrawings and the disclosed examples, which encompass all such aspectsand their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

The features, nature, and advantages of the present disclosure willbecome more apparent from the detailed description set forth below whentaken in conjunction with the drawings in which like referencecharacters identify like elements correspondingly throughout thespecification and drawings.

FIG. 1 is a screenshot showing results of a prior method for renderingextended video in virtual reality.

FIG. 2 is a perspective view of a three-dimensional (3D) mesh used forrendering extended video in virtual reality, using a cylindricalgeometry.

FIG. 3A is a top view of the 3D mesh show in FIG. 2, illustratingcertain geometric parameters of the novel mesh for rendering extendedvideo.

FIG. 3B is a side view of the 3D mesh shown in FIGS. 2 and 3A.

FIG. 4 is a perspective view of an alternative three-dimensional meshfor rendering extended video in virtual reality, using a sphericalgeometry.

FIG. 5 is a block diagram illustrating a content consumption device forconsuming VR or AR content.

FIG. 6 is a schematic diagram illustrating components of a stereoscopicdisplay device for presenting extended video in virtual reality.

FIG. 7 is a flow chart illustrating a method for transforming extendedvideo for display in virtual reality.

FIG. 8 is a conceptual block diagram illustrating components of anapparatus or system for transforming extended video for display invirtual reality.

FIG. 9 is a flow chart illustrating a method for presenting extendedvideo in virtual reality.

FIG. 10 is a conceptual block diagram illustrating components of anapparatus or system for presenting extended video in virtual reality.

DETAILED DESCRIPTION

Various aspects are now described with reference to the drawings. In thefollowing description, for purposes of explanation, numerous specificdetails are set forth in order to provide a thorough understanding ofone or more aspects. It may be evident, however, that the variousaspects may be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to facilitate describing these aspects.

Transforming extended video data for display in virtual realityrendering on virtual screens including a center screen and speciallyconfigured auxiliary screens. The auxiliary screens and theirrelationship to the center screen are characterized by special geometricparameters that differ from the real auxiliary screens for which theextended video data is produced. FIGS. 2, 3A and 3B illustrate variousaspects of these special parameters.

FIG. 2 shows a perspective view of a system 200 of virtual screensincluding a virtual center screen 210, a virtual left auxiliary screen220 and a virtual right auxiliary screen 230. Each of the virtualscreens 210, 220, 230 are modeled as a three-dimensional (3D) mesh in avirtual space denoted by the Cartesian tri-axial icon 240. The virtualspace can be defined using any suitable coordinate system, but it may beconvenient to use a system having its origin centered between the left220 and right 230 virtual screens and located on a base plane or virtualfloor. In the illustrated system 200, the lower edges of all the virtualscreens 210, 220, 230 are vertically aligned in a plane parallel to andlocated a distance ‘z₁’ above a floor plane. The upper edges of thevirtual screens are in a second plane also vertically aligned parallelto the floor plane and located a distance ‘z₂’ above it. Units used forthe virtual coordinate system are arbitrary, but the scale of thevirtual screens 210, 220, 230 relative to a reference floor does impactthe user experience. Advantageously, the scale may be selected such thatmotion of the user in the real world while wearing virtual reality gearcorresponds 1-to-1, within the limits of human perception, to movementof the virtual viewpoint. For example, the scale may be selected suchthat real movement of 100 centimeters corresponds to virtual movement ofthe virtual viewpoint that is 100 virtual centimeters in the samedirection, or that is about 100 virtual centimeters such that most userswill not notice discrepancies between real and actual movement. Forfurther example, in one embodiment, z₁=300 cm and z₂=330 cm. Furthergeometric parameters are discussed below in connection with FIGS. 3A-B.

FIG. 3A shows a top view 300 of a virtual screen setup including acenter virtual screen 318, a left (from the user's point of view)auxiliary screen 306 and a right auxiliary screen 302. The marker 308indicates a default position of the virtual viewpoint, along thecenterline 312 of the center screen 318 and slightly forward of the rearedges of the auxiliary screens 302, 306. When first activating thevirtual viewing space, the user's viewpoint for rendering the virtualscreens may be placed at the indicated default location 308, or at asimilar location that affords a balanced peripheral view of theauxiliary screens 302, 306 and that is aligned with and oriented towardsa center of the center screen 318, for example, towards a center of areaor aligned with a vertical center line of the center screen 318.

In some embodiments, the user may be free to move about within thevirtual space, based on feedback from motion sensors in the virtualreality gear or ancillary input device. In such embodiments, it may bedesirable to limit virtual movement to a confined area, for example to adefined volume 322 as indicated by the dashed rectangle. Such limitsprevent the user from inadvertently or intentionally moving to aposition where the video content on the virtual screens cannot readilybe seen or that is disorienting to the user.

Each of the virtual screens 302, 306, 318 may be of the same, orapproximately the same, size and shape. The computer positions andorients the virtual auxiliary screens such that imaginary tangent lines314, 316 to each of the auxiliary screens 302, 320 at their respectivecenters of area (i.e., where the center line 310 intersects theauxiliary screens 302, 306) intersect with an imaginary tangent line 316to the center screen at its center of area (i.e., where the center line312 intersects the center screen 318) at equal angles α₁=α₂. In theillustrated embodiment, α₁ and α₂ equal 90 degrees. Other values near 90degrees may also be suitable, for example, α₁ and α₂ may equal an anglein the range of 75 to 105 degrees.

A small vertically aligned gap of constant width ‘G’ may be insertedbetween the center screen 318 and each of the auxiliary screens 302,306. The purpose of the gap may be to obscure misalignment or othermismatch between the content appearing on the center screen and thatappearing on the auxiliary screens and/or to avoid the appearance of acrease where the screens meet. The gap may be selected to match asimilar gap in real extended video setups, to minimize processingrequired in adapting extended video content to virtual reality. In theIllustrated embodiment, the gap ‘G’ is 20 cm.

In an aspect, each of the screens 302, 318, 306 may be characterized byhaving a cylindrical radius of curvature ‘R’ in a plane parallel to topand bottom edge of each virtual screen. Flat virtual screens may beused, but cylindrically curved screens as depicted in the FIGS. 2-3B arebelieved to provide a greater immersive effect while avoiding noticeabledistortion of extended video output. In a human-scale setup, the valueof ‘R’ may be based on one or more pertinent screen measurements. Forexample, ‘R’ may be based on a ratio R/z₂ to a desired value of ‘z₂’,which indicates height of each of the virtual screens above a floor orreference plan. In the illustrated embodiment, ‘R’ is about 840 cm and‘z₂’ is about 300 cm, for a ratio of R/z₂ equal to about 2.8. Otherratios near 2.8 may also be suitable, for example, a ratio in a range of1 to 4, or higher. The ratio R/z₂ for flat virtual screens is infinite,because the radius ‘R’ is infinite. In an alternative, or in addition,the value of ‘R’ may be based on the distance from the default viewpoint308 to the screen 318 along the centerline 312. In the illustratedembodiment, this distance is also about 840 cm.

Each of the virtual screens 302, 318, 306 has a width ‘W’ measured alongits respective one of the tangent lines 314, 316, 320 such that a ratioof screen width to screen height (W/z₂) is in a range of 1.8 to 3.6. Inthe illustrated embodiment, the width is 790 cm and the height is 330cm, so this ratio is about 2.4. The virtual auxiliary screens 302, 306face each other, are symmetrically arranged on opposite sides of thecenter screen 318 and are spaced apart a distance ‘2C’ measured at theirrespective centers of area, wherein a ratio of 2C/W is in a range of 1to 1.5. In the illustrated embodiment, the distance ‘C’ is 490 cm, sothe ratio of 2C/W is about 1.24.

Referring to FIG. 3B, a side view 350 of the same screens as shown inFIG. 3A is illustrated. The auxiliary screens 302, 306 are fullyoverlapping in this view, which appears the same whether taken from theright or the left. The center screen 318 appears at the far right of thefigure. A side view of the motion constraint volume 322 is indicated bythe dashed rectangle. As noted previously, the screen configuration mayinclude a virtual floor plane 352 parallel to and located a distance‘z₁’ below the bottom edge of each virtual screen 302, 306, 318. Thedistance z₂ indicates the screen height between its top and bottomedges. The value of z₁ may be equal to or within 20% of 0.9*z₂. Forexample, for a screen height of 330 cm, the height of the bottom edge(i.e., screen elevation or ‘z₁’) may be about 300 cm.

The distance z₃ indicates the height of the default viewpoint above thefloor plane 352. In the illustrated embodiment, the distance z₃ is equalto one-half of the screen height z₂ plus z₁, which for this embodimentis 165+300=465 cm. The viewpoint height may thus be determined from thescreen height z₂ and elevation z₁. Ratios of screen height to width maybe as described above. The ratio of z₃/z₂ may be equal to 1.4, or in therange of 0.5 (when the screen touches the floor) to about 2. A range ofabout 1.3 to 1.5 may be preferable for most setups. In some embodiments,the screen elevation z₁ may be determined based on the screen height z₂and an estimated or measured real eye height of the user ‘h_(u)’ basedon the formula z₃=h_(u)=z₂/2+z₁, which when given h_(u) and solving forz₁ yields z₁=h_(u)−z₂/2. If z₂/2>h_(u), then z₁ should be negative(above the level of the bottom screen edge) and the floor plane 352should be invisible so that the effect is as standing on glass. Forusers who prefer a more solid virtual floor, z₂ should be selected sothat z₂/2<=h_(u). In a virtual environment, the relative sizes ofobjects in the environment that determines how the user perceives scale.For example, it makes no difference to the end user if all the virtualdimensions are scaled by some constant value. In the virtualenvironment, the user has no way of perceiving absolute scale, unlessthere is some error in rendering due to rendering parameters that areinappropriate for the chosen scale.

While FIGS. 2-3B show virtual screens with cylindrical curvatures, in analternative each of the virtual screens 404, 406, 408 may becharacterized by having a spherical radius of curvature Φ with a commoncenter 412, as shown in FIG. 4. The effect of the system 400 may be asif the user 410 was standing in a hemispherical chamber of radius Φ orlarger on which the extended video content is projected. Other virtualscreen dimensions may be as previously described.

The foregoing methods ad concepts may be implemented using any suitablevirtual reality (VR) display apparatus. Referring to FIG. 5, aspects ofa VR display apparatus 500 are illustrated. The apparatus 500 mayinclude, for example, a processor 502, for example a central processingunit based on 80×86 architecture as designed by Intel™ or AMD™, asystem-on-a-chip as designed by ARM™, or any other suitablemicroprocessor. The processor 502 may be communicatively coupled toauxiliary devices or modules of the VR display apparatus 500, using abus or other coupling. Optionally, the processor 502 and some or all ofits coupled auxiliary devices or modules (examples of which are depictedat 504-516) may be housed within or coupled to a housing 518, forexample, a housing having a form factor of a personal computer, gamingconsole, smart phone, notepad computer, laptop computer, set-top box,wearable googles, glasses, or visors, or other form factor.

A user interface device 504 may be coupled to the processor 502 forproviding user control input to an immersive content display processoperated by a VR immersive display engine executing on the processor502. User control input may include, for example, selections from agraphical user interface or other input (e.g., textual or directionalcommands) generated via a touch screen, keyboard, pointing device (e.g.,game controller), microphone, motion sensor, camera, or some combinationof these or other input devices. Control input may also be provided viaa sensor 506 coupled to the processor 502. A sensor may comprise, forexample, a motion sensor (e.g., an accelerometer), a position sensor, abiometric temperature or pulse sensor, a location sensor (for example, aGlobal Positioning System (GPS) receiver and controller), a multi-cameratracking sensor/controller, an eye-tracking sensor, or a microphone. Thesensor 506 may detect a motion or other state of a user interfacedisplay, for example, motion of a virtual-reality headset, or the bodilystate of the user, for example, facial expression, skin temperature,pupillary response (e.g., pupil dilation), corneal deformation, gazedirection, respiration rate, muscle tension, nervous system activity, orpulse.

The device 500 may optionally include an input/output port 508 coupledto the processor 502, to enable communication between a VR engine and acomputer network, for example a cinema content server or home theaterserver. Such communication may be used, for example, to enablemultiplayer VR experiences, including but not limited to sharedimmersive experiencing of cinematic content. The system may also be usedfor non-cinematic multi-user applications, for example socialnetworking, group entertainment experiences, instructional environments,video gaming, and so forth.

A display 510 may be coupled to the processor 502, for example via agraphics processing unit (not shown) integrated in the processor 502 orin a separate chip. The display 510 may include, for example, a flatscreen color liquid crystal (LCD) display illuminated by light-emittingdiodes (LEDs) or other lamps, a projector driven by an LCD display or bya digital light processing (DLP) unit, a laser projector, or otherdigital display device. The display device 510 may be incorporated intoa virtual reality headset or other immersive display system. Videooutput driven by a VR immersive display engine operating on theprocessor 502, or other application for coordinating user inputs with animmersive content display and/or generating the display, may be providedto the display device 510 and output as a video display to the user.Similarly, an amplifier/speaker or other audio output transducer 522 maybe coupled to the processor 502 via an audio processing system. Audiooutput correlated to the video output and generated by the VR/AR displayengine or other application may be provided to the audio transducer 522and output as audible sound to the user.

The VR display apparatus 500 may further include a random access memory(RAM) 514 holding program instructions and data for rapid execution orprocessing by the processor during controlling a 3D environment. Whenthe device 500 is powered off or in an inactive state, programinstructions and data may be stored in a long-term memory, for example,a non-volatile magnetic, optical, or electronic memory storage device516. Either or both of the RAM 514 or the storage device 516 maycomprise a non-transitory computer-readable medium holding programinstructions, that when executed by the processor 502, cause the device500 to perform a method or operations as described herein. Programinstructions may be written in any suitable high-level language, forexample, C, C++, C#, or Java™, and compiled to produce machine-languagecode for execution by the processor. Program instructions may be groupedinto functional modules, to facilitate coding efficiency andcomprehensibility. It should be appreciated that such modules, even ifdiscernable as divisions or grouping in source code, are not necessarilydistinguishable as separate code blocks in machine-level coding. Codebundles directed toward a specific type of function may be considered tocomprise a module, regardless of whether or not machine code on thebundle can be executed independently of other machine code. In otherwords, the modules may be high-level modules only.

Any of the features described herein may be executed by an applicationfor providing a 3D environment responsive to user input that produces VRoutput for an immersive VR headset or the like. FIG. 6 is a schematicdiagram illustrating one type of an immersive VR stereoscopic displaydevice 600 (also referred to herein as a VR display apparatus) that maybe provided in various form factors, of which device 600 provides butone example. The innovative methods, apparatus and systems are notnecessarily limited to a particular form factor of immersive VR display,but may be used in a video output device that enables the user tocontrol a position or point of view of video content playing on thedevice. Likewise, a VR output device may manage an audio position orpoint of view of audio content playing on the device. The immersive VRstereoscopic display device 600 represents an example of a relativelylow-cost device designed for consumer use.

The immersive VR stereoscopic display device 600 may include a tabletsupport structure made of an opaque lightweight structural material(e.g., a rigid polymer, aluminum or cardboard) configured for supportingand allowing for removable placement of a portable tablet computing orsmartphone device including a high-resolution display screen, forexample, an LCD display. This modular design may avoid the need fordedicated electronic components for video output, greatly reducing thecost. The device 600 is designed to be worn close to the user's face,enabling a wide field of view using a small screen size such astypically found in present handheld tablet computing or smartphonedevices. The support structure 626 may provide a fixed mounting for apair of lenses 622 held in relation to the display screen 612. Thelenses may be configured to enable the user to comfortably focus on thedisplay screen 612 which may be held approximately one to three inchesfrom the user's eyes.

The device 600 may further include a viewing shroud (not shown) coupledto the support structure 626 and configured of a soft, flexible or othersuitable opaque material for form fitting to the user's face andblocking outside light. The shroud may be configured to ensure that theonly visible light source to the user is the display screen 612,enhancing the immersive effect of using the device 600. A screen dividermay be used to separate the screen 612 into independently drivenstereoscopic regions, each of which is visible only through acorresponding one of the lenses 622. Hence, the immersive VRstereoscopic display device 600 may be used to provide stereoscopicdisplay output, providing a more realistic perception of 3D space forthe user. Two separate displays can also be used to provide independentimages to the user's left and right eyes respectively. It should beappreciated that the present technology may be used for, but is notnecessarily limited to, stereoscopic video output.

The immersive VR stereoscopic display device 600 may further comprise abridge (not shown) for positioning over the user's nose, to facilitateaccurate positioning of the lenses 622 with respect to the user's eyes.The device 600 may further comprise an elastic strap or band 624, orother headwear for fitting around the user's head and holding the device600 to the user's head.

The immersive VR stereoscopic display device 600 may include additionalelectronic components of a display and communications unit 602 (e.g., atablet computer or smartphone) in relation to a user's head 630. Asupport structure 604 holds the display and communications unit 602using restraining device 624 that is elastic and/or adjustable toprovide a comfortable and secure snug fit, for example, adjustableheadgear. When wearing the support 602, the user views the display 612though the pair of lenses 622. The display 612 may be driven by theCentral Processing Unit (CPU) 602 and/or Graphics Processing Unit (GPU)610 via an internal bus 616. Components of the display andcommunications unit 602 may further include, for example, atransmit/receive component or components 618, enabling wirelesscommunication between the CPU and an external server via a wirelesscoupling. The transmit/receive component 618 may operate using anysuitable high-bandwidth wireless technology or protocol, including, forexample, cellular telephone technologies such as 3rd GenerationPartnership Project (3GPP) Long Term Evolution (LTE), Global System forMobile communications (GSM) or Universal Mobile TelecommunicationsSystem (UMTS), and/or a wireless local area network (WLAN) technologyfor example using a protocol such as Institute of Electrical andElectronics Engineers (IEEE) 802.11. The transmit/receive component orcomponents 618 may enable streaming of video data to the display andcommunications unit 602 from a local or remote video server, and uplinktransmission of sensor and other data to the local or remote videoserver any desired purpose.

Components of the display and communications unit 602 may furtherinclude, for example, one or more sensors 614 coupled to the CPU 606 viathe communications bus 616. Such sensors may include, for example, anaccelerometer/inclinometer array providing orientation data forindicating an orientation of the display and communications unit 602. Asthe display and communications unit 602 is fixed to the user's head 630,this data may also be calibrated to indicate an orientation of the head630. The one or more sensors 614 may further include, for example, aGlobal Positioning System (GPS) sensor indicating a geographic positionof the user. The one or more sensors 614 may further include, forexample, a camera or image sensor positioned to detect an orientation ofone or more of the user's eyes. In some embodiments, a camera, imagesensor, or other sensor configured to detect a user's eyes, gazedirection, pupillary response and/or eye movements may be mounted in thesupport structure 626 and coupled to the CPU 606 via the bus 616 and aserial bus port (not shown), for example, a Universal Serial Bus (USB)or other suitable communications port. The one or more sensors 614 mayfurther include, for example, an interferometer positioned in thesupport structure 604 and configured to indicate a surface contour tothe user's eyes. The one or more sensors 614 may further include, forexample, a microphone, array or microphones, or other audio inputtransducer for detecting spoken user commands or verbal and non-verbalaudible reactions to display output. The one or more sensors mayinclude, for example, electrodes or microphone to sense heart rate, atemperature sensor configured for sensing skin or body temperature ofthe user, an image sensor coupled to an analysis module to detect facialexpression or pupil dilation, a microphone to detect verbal andnonverbal utterances, or other biometric sensors for collectingbiofeedback data.

Components of the display and communications unit 602 may furtherinclude, for example, an audio output transducer 620, for example aspeaker or piezoelectric transducer in the display and communicationsunit 602 or audio output port for headphones or other audio outputtransducer mounted in headgear 624 or the like. The audio output devicemay provide surround sound, multichannel audio, so-called ‘objectoriented audio’, or other audio track output accompanying a stereoscopicimmersive VR video display content. Components of the display andcommunications unit 602 may further include, for example, a memorydevice 608 coupled to the CPU 606 via a memory bus. The memory 608 maystore, for example, program instructions that when executed by theprocessor cause the apparatus 600 to perform operations as describedherein. The memory 608 may also store data, for example, audio-videodata in a library or buffered during streaming operations. Furtherdetails regarding generation and use of VR environments may be asdescribed in U.S. patent application Ser. No. 14/960379, filed Dec. 5,2015, which is incorporated herein in its entirety by reference.

In view the foregoing, and by way of additional example, FIG. 7 showsaspects of a method 700 for transforming extended video data for displayin virtual reality. The method 700 may be performed by one or moreprogrammable computers for transforming extended video content into VRcontent rendered on three screens, for example, by a productioncomputer, by a VR display apparatus as described in connection withFIGS. 5-6, or by any useful combination of the foregoing. The method 700may include, at 710, receiving digital extended video data for displayon a center screen and two auxiliary screens of a real extended videocinema. The extended video data may include 2D video data, 3D(stereoscopic) video data, or both produce for projection or otherdisplay on three physical screens in a cinema setting.

The method 700 may include, at 720, accessing, by a computer executing arendering application, data that defines virtual screens including acenter screen and auxiliary screens. The computer may define geometry ofthe virtual center and auxiliary screens as described above inconnection with FIGS. 2-3B. For example, the computer may position andorient the virtual screens such that tangent lines to each of theauxiliary screens at their respective centers of area intersect with atangent line to the center screen at its center of area at equal anglesin a range of 75 to 105 degrees.

The method 700 may include, at 730, preparing virtual extended videodata at least in part by rendering the digital extended video oncorresponding ones of the virtual screens from a defined viewpoint. Therendering result may further be transformed into one or more formats foruse in a virtual reality display device.

For alternative embodiments that support real-time rendering by adownstream VR display apparatus, the method 700 may include, at 735,preparing pre-rendering virtual extended video data at least in part byassociating the digital extended video with corresponding ones of thevirtual screens, without rendering an output image. In theseembodiments, the extended video data is prepared for rendering by or inconnection with the downstream VR display device at runtime. This allowsthe user's viewpoint to move in the virtual reality environment,providing a more immersive experience.

The method 700 may include, at 740, saving the virtual extended memoryand/or pre-rendering video data in a computer memory for use by thevirtual reality display device. For example, the data may be saved in afile for long term storage, held in a short-term cache for displayoutput, or both.

FIG. 8 is a conceptual block diagram illustrating components of anapparatus or system 800 for transforming extended video data for displayin virtual reality, as described herein. The apparatus or system 800 mayinclude additional or more detailed components for performing functionsor process operations as described herein. For example, the processor810 and memory 814 may contain an instantiation of a process fortransforming extended video data for display in virtual reality. Asdepicted, the apparatus or system 800 may include functional blocks thatcan represent functions implemented by a processor, software, orcombination thereof (e.g., firmware). The apparatus 800 may be aproduction computer, a VR display apparatus, or a combination of theforegoing.

As illustrated in FIG. 8, the apparatus or system 800 may comprise anelectrical component 802 for receiving digital extended video data fordisplay on a center screen and two auxiliary screens of a real extendedvideo cinema. The component 802 may be, or may include, a means for saidreceiving. Said means may include the processor 810 coupled to thememory 814, and to a data input/output interface 812, the processorexecuting an algorithm based on program instructions stored in thememory. Such algorithm may include a sequence of more detailedoperations, for example, connecting to a node holding the digitalextended video data, establishing a data transfer session, andtransferring the digital extended video data to a local memory.

The apparatus 800 may further include an electrical component 804 foraccessing, by a computer executing a rendering application, data thatdefines virtual screens including a center screen and auxiliary screens.The virtual center and auxiliary screens may be characterized bygeometry as described above in connection with FIGS. 2-3B. The component804 may be, or may include, a means for said accessing. Said means mayinclude the processor 810 coupled to the memory 814, the processorexecuting an algorithm based on program instructions stored in thememory. Such algorithm may include a sequence of more detailedoperations, for example, opening a data file using a renderingapplication or a component of a rendering application suite, wherein thedata file defines 3D geometry of the virtual center and auxiliaryscreens in a format readable by the rendering application or component.

The apparatus 800 may further include an electrical component 806 forpreparing virtual extended video data at least in part by rendering thedigital extended video on corresponding ones of the video screens. Thecomponent 806 may be, or may include, a means for said preparing. Saidmeans may include the processor 810 coupled to the memory 814, theprocessor executing an algorithm based on program instructions stored inthe memory. Such algorithm may include a sequence of more detailedoperations, for example, for each frame of video data and for eachscreen, setting rendering parameters based on default values, userinput, or both, providing the 3D geometry of the virtual center andauxiliary screens and the rendering parameters to a rendering engine,determining pixel values of a video frame by the rendering engine basedon the provided information. In alternative embodiments, the algorithmmay include creating pre-rendering data as described at 735 by aproduction computer and performing the rendering operation in real timeby a VR display apparatus. The algorithm may further include, for eachscreen, compiling rendered frames of video into a digital video file orcache memory for display output.

The apparatus 800 may further include an electrical component 807 forsaving the virtual extended video data in a computer memory. Thecomponent 807 may be, or may include, a means for said saving. Saidmeans may include the processor 810 coupled to the memory 814, theprocessor executing an algorithm based on program instructions stored inthe memory. Such algorithm may include a sequence of more detailedoperations, for example, creating a data file containing the virtualextended video data in a format usable by a VR output device, providingthe data file to a memory device, and writing the data file to a memorycomponent of the memory device.

The apparatus 800 may optionally include a processor module 810 havingat least one processor. The processor 810 may be in operativecommunication with the modules 802-807 via a bus 813 or similarcommunication coupling. The processor 810 may effect initiation andscheduling of the processes or functions performed by electricalcomponents 802-807.

In related aspects, the apparatus 800 may include a data interfacemodule 812 operable for communicating with system components over acomputer network. A data interface module may be, or may include, forexample, an Ethernet port or serial port (e.g., a Universal Serial Bus(USB) port). In further related aspects, the apparatus 800 mayoptionally include a module for storing information, such as, forexample, a memory device 814. The computer readable medium or the memorymodule 814 may be operatively coupled to the other components of theapparatus 800 via the bus 813 or the like. The memory module 814 may beadapted to store computer readable instructions and data for effectingthe processes and behavior of the modules 802-807, and subcomponentsthereof, or the processor 810, or the method 700. The memory module 814may retain instructions for executing functions associated with themodules 802-807. While shown as being external to the memory 814, it isto be understood that the modules 802-807 can exist within the memory814.

The apparatus 800 may include a transceiver configured as a wirelesstransmitter/receiver, or a wired transmitter/receiver, for transmittingand receiving a communication signal to/from another system component.In alternative embodiments, the processor 810 may include networkedmicroprocessors from devices operating over a computer network. Inaddition, the apparatus 800 may communicate with a stereographic displayor other immersive display device for displaying immersive content.

Referring to FIG. 9, a computer-implemented method for processingextended video data for display by a virtual reality display apparatusmay include, at 910, accessing, by a virtual reality display apparatus,virtual extended video data for display that defines virtual screensincluding a center screen and auxiliary screens. The virtual center andauxiliary screens may be characterized by geometry as described above inconnection with FIGS. 2-3B. For example, tangent lines to each of theauxiliary screens at their respective centers of area intersect with atangent line to the center screen at its center of area at equal anglesin a range of 75 to 105 degrees, and other geometric features as havealready been described in detail herein above. The method 900 mayinclude, at 920, outputting the virtual extended video data for displayusing a stereographic display system of the VR headset, and optionally,displaying the virtual extended video data on the display. Any suitableVR display method may be used consistent with the geometry describedabove. In an aspect, the method 900 may further include receiving outputfrom one or more sensors of the VR display apparatus, changing therendering viewpoint based on the sensor output, and rendering one ormore video frames of the extended video content based on the renderingviewpoint, virtual screen geometry, extended video data and otherrendering parameters, to provide a more immersive experience. In suchembodiments, the method may further include limiting movement of therendering viewpoint to within a defined volume 322 as described inconnection with FIGS. 3A-B.

FIG. 10 is a conceptual block diagram illustrating components of anapparatus or system 1000 for processing extended video data for displayby a virtual reality display apparatus, as described herein. Theapparatus or system 1000 may include additional or more detailedcomponents for performing functions or process operations as describedherein. For example, the processor 1010 and memory 1014 may contain aninstantiation of a process for processing extended video data fordisplay by a virtual reality display apparatus using virtual screens asdescribed herein above. As depicted, the apparatus or system 1000 mayinclude functional blocks that can represent functions implemented by aprocessor, software, or combination thereof (e.g., firmware).

As illustrated in FIG. 10, the apparatus or system 1000 may comprise anelectrical component 1002 for accessing, by a virtual reality displayapparatus, virtual extended video data for display that defines virtualscreens including a center screen and auxiliary screens. The virtualcenter and auxiliary screens may be characterized by geometry asdescribed above in connection with FIGS. 2-3B. For example, tangentlines to each of the auxiliary screens at their respective centers ofarea intersect with a tangent line to the center screen at its center ofarea at equal angles in a range of 75 to 105 degrees, and othergeometric features as have already been described in detail hereinabove. The component 1002 may be, or may include, a means for saidaccessing. Said means may include the processor 1010 coupled to thememory 1014, the transceiver 1012, and to the stereographic display1016, the processor executing an algorithm based on program instructionsstored in the memory. Such algorithm may include a sequence of moredetailed operations, for example, opening a data file, or connecting toa data stream, using a real-time VR rendering application or componentthereof, wherein the data file defines 3D geometry of the virtual centerand auxiliary screens in a format readable by the rendering applicationor component.

The apparatus 1000 may further include an electrical component 1004 fordisplaying the virtual extended video data using a stereographic displaysystem of the VR headset. The component 1004 may be, or may include, ameans for said displaying. Said means may include the processor 1010coupled to the memory 1014 and to a sensor (not shown), the processorexecuting an algorithm based on program instructions stored in thememory. Such algorithm may include a sequence of more detailedoperations, for example, receiving output from one or more sensors ofthe VR display apparatus, changing the rendering viewpoint based on thesensor output, and rendering one or more video frames of the extendedvideo content in real time based on the rendering viewpoint, virtualscreen geometry, extended video data and other rendering parameters,outputting the virtual extended video data for display using astereographic display system of the VR headset, and optionally,displaying the virtual extended video data on the display.

The apparatus 1000 may optionally include a processor module 1010 havingat least one processor. The processor 1010 may be in operativecommunication with the modules 1002-1004 via a bus 1013 or similarcommunication coupling. The processor 1010 may effect initiation andscheduling of the processes or functions performed by electricalcomponents 1002-1004.

In related aspects, the apparatus 1000 may include a network interfacemodule (not shown) operable for communicating with system componentsover a computer network, instead of or in addition to the transceiver1012. A network interface module may be, or may include, for example, anEthernet port or serial port (e.g., a Universal Serial Bus (USB) port).In further related aspects, the apparatus 1000 may optionally include amodule for storing information, such as, for example, a memory device1014. The computer readable medium or the memory module 1014 may beoperatively coupled to the other components of the apparatus 1000 viathe bus 1013 or the like. The memory module 1014 may be adapted to storecomputer readable instructions and data for effecting the processes andbehavior of the modules 1002-1004, and subcomponents thereof, or theprocessor 1010, or the method 900 and one or more of the additionaloperations disclosed herein in connection with method 900. The memorymodule 1014 may retain instructions for executing functions associatedwith the modules 1002-1004. While shown as being external to the memory1014, it is to be understood that the modules 1002-1004 can exist withinthe memory 1014.

The apparatus 1000 may include a data input/output component 1012, forexample, any one or more of a wireless transmitter/receiver, a wiredtransmitter/receiver, a sensor array, or network interface, fortransmitting and receiving a communication signal to/from another systemcomponent. In alternative embodiments, the processor 1010 may includenetworked microprocessors from devices operating over a computernetwork. In addition, the apparatus 1000 may include a stereographicdisplay or other immersive display device 1016 for displaying immersivecontent. The stereographic display device 1016 may be, or may include,any suitable stereographic AR or VR output device as described hereinabove, or as otherwise known in the art.

Those of skill would further appreciate that the various illustrativelogical blocks, modules, circuits, and algorithm steps described inconnection with the aspects disclosed herein may be implemented aselectronic hardware, computer software, or combinations of both. Toclearly illustrate this interchangeability of hardware and software,various illustrative components, blocks, modules, circuits, and stepshave been described above generally in terms of their functionality.Whether such functionality is implemented as hardware or softwaredepends upon the particular application and design constraints imposedon the overall system. Skilled artisans may implement the describedfunctionality in varying ways for each particular application, but suchimplementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

As used in this application, the terms “component”, “module”, “system”,and the like are intended to refer to a computer-related entity, eitherhardware, a combination of hardware and software, software, or softwarein execution. For example, a component or a module may be, but are notlimited to being, a process running on a processor, a processor, anobject, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on aserver and the server can be a component or a module. One or morecomponents or modules may reside within a process and/or thread ofexecution and a component or module may be localized on one computerand/or distributed between two or more computers.

Various aspects will be presented in terms of systems that may include anumber of components, modules, and the like. It is to be understood andappreciated that the various systems may include additional components,modules, etc. and/or may not include all of the components, modules,etc. discussed in connection with the figures. A combination of theseapproaches may also be used. The various aspects disclosed herein can beperformed on electrical devices including devices that utilize touchscreen display technologies, heads-up user interfaces, wearableinterfaces, and/or mouse-and-keyboard type interfaces. Examples of suchdevices include VR output devices (e.g., VR headsets), AR output devices(e.g., AR headsets), computers (desktop and mobile), smart phones,personal digital assistants (PDAs), and other electronic devices bothwired and wireless.

In addition, the various illustrative logical blocks, modules, andcircuits described in connection with the aspects disclosed herein maybe implemented or performed with a general purpose processor, a digitalsignal processor (DSP), an application specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic device, discrete gate or transistor logic, discrete hardwarecomponents, or any combination thereof designed to perform the functionsdescribed herein. A general purpose processor may be a microprocessor,but in the alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

Operational aspects disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. A software module may reside in RAM memory,flash memory, ROM memory, EPROM memory, EEPROM memory, registers, harddisk, a removable disk, a CD-ROM, digital versatile disk (DVD),Blu-ray™, or any other form of storage medium known in the art. Anexemplary storage medium is coupled to the processor such the processorcan read information from, and write information to, the storage medium.In the alternative, the storage medium may be integral to the processor.The processor and the storage medium may reside in an ASIC. The ASIC mayreside in a client device or server. In the alternative, the processorand the storage medium may reside as discrete components in a clientdevice or server.

Furthermore, the one or more versions may be implemented as a method,apparatus, or article of manufacture using standard programming and/orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedaspects. Non-transitory computer readable media can include but are notlimited to magnetic storage devices (e.g., hard disk, floppy disk,magnetic strips, or other format), optical disks (e.g., compact disk(CD), DVD, Blu-ray™ or other format), smart cards, and flash memorydevices (e.g., card, stick, or other format). Of course, those skilledin the art will recognize many modifications may be made to thisconfiguration without departing from the scope of the disclosed aspects.

The previous description of the disclosed aspects is provided to enableany person skilled in the art to make or use the present disclosure.Various modifications to these aspects will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other embodiments without departing from the spirit or scopeof the disclosure. Thus, the present disclosure is not intended to belimited to the embodiments shown herein but is to be accorded the widestscope consistent with the principles and novel features disclosedherein.

In view of the exemplary systems described supra, methodologies that maybe implemented in accordance with the disclosed subject matter have beendescribed with reference to several flow diagrams. While for purposes ofsimplicity of explanation, the methodologies are shown and described asa series of blocks, it is to be understood and appreciated that theclaimed subject matter is not limited by the order of the blocks, assome blocks may occur in different orders and/or concurrently with otherblocks from what is depicted and described herein. Moreover, not allillustrated blocks may be required to implement the methodologiesdescribed herein. Additionally, it should be further appreciated thatthe methodologies disclosed herein are capable of being stored on anarticle of manufacture to facilitate transporting and transferring suchmethodologies to computers.

1. A method for transforming extended video data for display in virtualreality, the method comprising: receiving digital extended video datafor display on a center screen and two auxiliary screens of a realextended video cinema; accessing, by a computer executing a renderingapplication, data that defines virtual screens including a center screenand auxiliary screens, wherein tangent lines to each of the auxiliaryscreens at their respective centers of area intersect with a tangentline to the center screen at its center of area at equal angles in arange of 75 to 105 degrees; preparing virtual extended video data atleast in part by rendering the digital extended video on correspondingones of the virtual screens; and saving the virtual extended video datain a computer memory.
 2. The method of claim 1, wherein the data thatdefines the virtual screens further defines each of the auxiliaryscreens as having parallel tangents at their respective centers.
 3. Themethod of claim 1, wherein the data that defines the virtual screensfurther defines that each of the virtual screens is characterized by ahaving a cylindrical radius of curvature ‘R’ in a plane parallel to topand bottom edge of each virtual screen.
 4. The method of claim 3,wherein the data that defines the virtual screens further defines that aratio R/z₂ wherein ‘z₂’ indicates height of each of the virtual screensis in a range of 1 to 4, and further comprising accessing data thatdefines a virtual floor plane parallel to and located a distance ‘z₁’below the bottom edge of each virtual screen, wherein z₁ is equal to orwithin 20% of 0.9*z₂,
 5. The method of claim 4, wherein the data thatdefines the virtual screens further defines that each of the virtualscreens has a width W measured along its respective one of the tangentlines such that a ratio W/z₂ is in a range of 1.8 to 3.6.
 6. The methodof claim 6, wherein the data that defines the virtual screens furtherdefines that the auxiliary screens face each other and are spaced aparta distance ‘2C’ measured at their respective centers of area, wherein aratio of 2C/W is in a range of 1 to 1.5.
 7. The method of claim 1,wherein the data that defines the virtual screens further defines thateach of the virtual screens is characterized by a having a sphericalradius of curvature with a common center.
 8. An apparatus fortransforming extended video data for display in virtual reality,comprising: a processor, a memory coupled to the processor, and astereoscopic display device coupled to the processor, wherein the memoryholds instructions that when executed by the processor, cause theapparatus to perform the operations of: receiving digital extended videodata for display on a center screen and two auxiliary screens of a realextended video cinema; accessing, by a computer executing a renderingapplication, data that defines virtual screens including a center screenand auxiliary screens, wherein tangent lines to each of the auxiliaryscreens at their respective centers of area intersect with a tangentline to the center screen at its center of area at equal angles in arange of 75 to 105 degrees; preparing virtual extended video data atleast in part by rendering the digital extended video on correspondingones of the virtual screens; and saving the virtual extended video datain a computer memory.
 9. The apparatus of claim 9, wherein the memoryholds further instructions that defines each of the auxiliary screens ashaving at least one of parallel tangents at their respective centers ora spherical radius of curvature with a common center.
 10. The apparatusof claim 9, wherein the memory holds further instructions that defineseach of the virtual screens characterized by a having a cylindricalradius of curvature ‘R’ in a plane parallel to top and bottom edge ofeach virtual screen.
 11. The apparatus of claim 11, wherein the memoryholds further instructions that defines each of the virtual screens ashaving a ratio R/z₂ wherein ‘z₂’ indicates height of each of the virtualscreens is in a range of 1 to
 4. 12. The apparatus of claim 12, whereinthe memory holds further instructions that defines a virtual floor planeparallel to and located a distance ‘z₁’ below the bottom edge of eachvirtual screen, wherein z₁ is equal to or within 20% of 0.9*z₂, thateach of the virtual screens has a width ‘W’ measured along itsrespective one of the tangent lines such that a ratio W/z₂ is in a rangeof 1.8 to 3.6, that the auxiliary screens face each other and are spacedapart a distance ‘2C’ measured at their respective centers of area,wherein a ratio of 2C/W is in a range of 1 to 1.5.
 13. An apparatus forprocessing extended video data for display by a virtual reality displayapparatus, comprising: a processor, a memory coupled to the processor,and a stereoscopic display device coupled to the processor, wherein thememory holds instructions that when executed by the processor, cause theapparatus to perform: accessing virtual extended video data for displaythat defines virtual screens including a center screen and auxiliaryscreens, wherein tangent lines to each of the auxiliary screens at theirrespective centers of area intersect with a tangent line to the centerscreen at its center of area at equal angles in a range of 75 to 105degrees; and outputting the virtual extended video data for displayusing a stereographic display system of the VR headset.
 14. Theapparatus of claim 13, wherein the memory holds further instructionsthat define orientation of each of the auxiliary screens such that theirtangents are parallel.
 15. The apparatus of claim 13, wherein the memoryholds further instructions that define each of the virtual screenscharacterized by a having a cylindrical radius of curvature ‘R’ in aplane parallel to top and bottom edge of each virtual screen.
 16. Theapparatus of claim 15, wherein the memory holds further instructionsthat define a ratio R/z₂, wherein ‘z₂’ indicates height of each of thevirtual screens, in a range of 1 to
 4. 17. The apparatus of claim 16,wherein the memory holds further instructions that define a virtualfloor plane parallel to and located a distance ‘z₃’ below the bottomedge of each virtual screen, wherein z₃ is equal to or within 20% of0.9*z₂.
 18. The apparatus of claim 16, wherein the memory holds furtherinstructions that define each of the virtual screens has a width ‘W’measured along its respective one of the tangent lines such that a ratioW/z₂ is in a range of 1.8 to 3.6.
 19. The apparatus of claim 18, whereinthe memory holds further instructions that define that the auxiliaryscreens face each other and are spaced apart a distance ‘2C’ measured attheir respective centers of area, wherein a ratio of 2C/W is in a rangeof 1 to 1.5.
 20. The apparatus of claim 13, wherein the memory holdsfurther instructions that define that each of the virtual screens ischaracterized by a having a spherical radius of curvature with a commoncenter.